1. Field of the Invention
The described invention relates to the field of imaging. In particular, the invention relates to the recording and playing back of a video stream. A video stream includes any combination of audio and/or video data streams. However, the concepts disclosed may be applied to other types of data streams.
2. Description of Related Art
Video streams have typically been recorded on analog media such as a video cassette. A video cassette recorder (VCR) is used to record the video stream on the video cassette. The video stream may come via a broadcast signal, via cable, via satellite signal, or from another video playback device. Once the video stream has been recorded, the VCR is used to rewind the recording medium and play what was recorded. However, due to the nature of the analog medium, once the VCR has started recording, it is not possible to play back the portion of the video stream that has already been recorded until the recording session is terminated.
For example, imagine that a person sets up a VCR for recording a one hour show because he knows that he will miss the first 15 minutes of the show. When he arrives home 15 minutes into the show, he will have to wait for the entire show to be recorded before he can start watching the program from the beginning. A way of being able to view the show from the beginning without having to wait for the recording session to terminate is desirable.
A method of providing a time-shifted video stream is disclosed. A video stream is received at an input. The video stream is recorded to a storage unit. While the video stream continues to be recorded, a portion of the video stream is retrieved from the storage unit and provided at an output. In one embodiment, the storage unit is a random access storage unit, such as a hard disk.